As a method of voice searching that uses input voice which is a input voice from a user and searches a word string such as text or the like corresponding to the voice thereof, for example there is a method that uses only a voice recognition device (e.g., see PTL 1).
With voice searching that uses only a voice recognition device, in the voice recognition device, voice recognition of the input voice is performed on the array of words (vocabulary) registered beforehand in a dictionary, with voice recognition results as the object, and the voice recognition results thereof are output as a search result word string which is the result of searching for the word string corresponding to the input voice.
Accordingly, with the voice search that uses only a voice recognition device, the word string intended for search results of a word string corresponding to the input voice (hereafter, also called word string for search results) is only a word string which is an array of words registered in the dictionary (according to the present Specification, one word is included) which is intended for voice recognition results, whereby speech by the user is limited to the array of words registered in the dictionary used for voice recognition.
Now, in recent years, a voice searching method called voice search (Voice Search) has been proposed.
In Voice Search, a language model such as N-gram or the like is used to perform consecutive voice recognition, and matching of the voice recognition results and text that is registered in a DB (Database) prepared separately from the dictionary used for voice recognition (text searching of text corresponding to the voice recognition results from the text registered in the DB) is performed.
Subsequently, based on the matching results thereof, the text that is the highest ranking or that is within the top N places matching the voice recognition result is output as the search result word string.
With Voice Search, the text registered in the DB prepared separately from the dictionary used for voice recognition becomes the word string for search results, whereby, by registering multiple texts in the DB, the multiple texts thereof can be subjected to voice searching as word strings for search result.
That is to say, according to Voice Search, even if the user performs speech of words other than the words registered in the dictionary used for voice recognition, voice searching can be performed with a certain degree of accuracy within the range of the text serving as the word strings for search results registered in the DB.